By STEVEN M. DAVIDOFF

Published: April 25, 2012

You might think that if you bought shares of a Chinese company that was listed on an American stock market, you would actually own a piece of that company.

Unfortunately, it is not that simple. The recent cases of the ChinaCast Education Corporation and the Sino-Forest Corporation show that in many instances, foreign investors in Chinese companies might have bought shares that don't really represent much. It's a problem that has the potential to extend to even the soundest Chinese company listed in the United States.

The ChinaCast case is not the most egregious, but it is certainly the most scandalous. In March, its chief executive, Ron Chan, was ousted in a battle for shareholder control of the company. An American investor succeeded not only in replacing Mr. Chan, but also in obtaining control of the ChinaCast board.

Yet that turned out to be only the beginning of the battle.

Last week, ChinaCast disclosed that it could not find its company seals, or authorized signatures, for its Chinese subsidiary. Seals are necessary for ChinaCast's Chinese subsidiary to undertake any business in China. Without them, ChinaCast can't sign contracts or even pay employees. In other words, China appears to have ''Lord of the Rings'' corporate governance - one seal to rule them all.

Mr. Chan was believed to have possession of them but now claims to know nothing.

Two of the universities owned by ChinaCast appear to have been transferred to ChinaCast's former chief investment officer and president of its Chinese operations. And last week, according to the board, about a dozen people broke into the company's Shanghai office and stole a number of documents and computers.

ChinaCast has a revolt on its hands that it is finding difficult to quell.

One reason that ChinaCast is having a problem is that shareholders did not actually buy an interest in its operations. Instead, to avoid Chinese restrictions on foreign investment, ChinaCast's shareholders invested in a United States company that has contractual arrangements with a Chinese company. But the Chinese company remains in the ownership of Chinese citizens.

The problem with this structure, known as a variable interest entity, is that it may be illegal under Chinese law and has been criticized by Chinese regulators. Even if it is legal, if the Chinese owners decide to go rogue, the United States-listed entity must sue and obtain a judgment from a Chinese court to enforce these dubious contracts. Good luck with that. Such a litigation can take a long time to resolve, if ever.

In ChinaCast's case, it can't do anything until it has control of the corporate seals, but under Chinese law it needs them to sue to recover them. In the meantime, the operators of the Chinese subsidiary can take full advantage of the situation.

Unfortunately, ChinaCast is not the only Chinese company with dubious claims to its assets.

Sino-Forest, listed on the Toronto Stock Exchange, is the most prominent Chinese company to experience this problem. Last summer, Sino-Forest was accused by Muddy Waters Research of fraudulent accounting with respect to timber lands. At the time of the report, SinoForest had a $4 billion market capitalization.

A subsequent report by an independent committee of directors denied that there was a practice of fraud at the company, but also acknowledged that much of Sino-Forest's property was held through a variable interest entity, or otherwise under contractual rights without an actual title.

Sino-Forest has filed for bankruptcy in Canada. Its assets far exceed its liabilities, but shareholders are likely to end up with nothing, in part because Sino-Forest's rights to its assets are tenuous at best.

The variable interest entity structure may be the root of the problem when foreign investors own shares in Chinese companies, but it is only part of it. The norms for business are different in China, and enforcing legal contracts or rights is sometimes impossible. Legal title to assets is often not formalized, and even when it is, Chinese executives can use the lack of rule of law to take advantage of foreign shareholders.

Other disputes show that ownership of assets in China can be fleeting.

Yahoo got into a tussle with Jack Ma, the chairman and chief executive of the Alibaba Group, in which Yahoo has a substantial interest, when he transferred Alibaba's online payment platform, Alipay, to a private company controlled by him. Mr. Ma and Yahoo eventually resolved their disputes, but the transfer was a warning sign that Mr. Ma was willing to take all steps to ensure that the only buyers for Yahoo's Chinese assets were Mr. Ma and his co-investors.

In the case of Nasdaq-listed GigaMedia, a Singapore-based online gaming company, it wasn't the variable interest entity structure that did the company in. Instead, the head of its Chinese business simply made off with the seals for GigaMedia's Chinese company and transferred ownership of the assets. GigaMedia appears to have given up on getting the business back.